1. Field of the Invention
The present invention relates to mobile terminals. More particularly, the present invention relates to modifying web page links for display on a mobile terminal to indicate the cache status of linked web pages.
2. Description of the Prior Art
A mobile terminal, such as handheld computer, cellular phone, tablet computer, etc., may be used to browse web pages downloaded from the Internet off-line or on-line. Off-line browsing is typically performed after web pages from selected web sites have been transmitted to the mobile terminal during a synchronization session and cached in the local memory of the mobile terminal. FIG. 1 shows a prior art configuration for synchronizing a mobile terminal 2 to a target computer 4 over a direct, wired connection 6 (e.g., a USB connection). The target computer 4 is also typically connected to the Internet so that it may download web pages which are transmitted to the mobile terminal 2 during the synchronization session.
The user typically configures a “link-depth” which determines how deep within each web site links will be followed when synchronizing to the web site. The web pages are transmitted starting with a “root” web page and following through the links for the root web page in the order they are encountered until all of the links have been transmitted for the specified “link-depth”, or until the memory allocated for the web site is exhausted. If a “dead” link is encountered during the synchronization session (meaning that the linked web page cannot be found), the “dead” link is still transmitted with the current web page. All of the links at the end of the “link-depth” are “dead” links since the corresponding linked web pages are not transmitted to the mobile terminal. Similarly, if the memory is exhausted during the synchronization session, the remaining links of the current web page as well as the remaining links on the root web page will be “dead” links. When the user is browsing the web pages off-line and clicks on a “dead” link, an error message is displayed indicating that the linked web page is not available. This degrades the perceived performance of the mobile terminal since the user cannot discern a “dead” link and therefore will waste time clicking on “dead” links.
A similar performance degradation occurs when the user is browsing the Internet on-line, for example, over a wireless connection. FIG. 2 shows prior art configurations for browsing the Internet 8 wherein in one configuration, the mobile terminal 2 accesses the Internet 8 over a wired connection 10 (e.g., telephone lines) and an Internet service provider (ISP) 12. In another configuration, the mobile terminal 2 accesses the Internet 8 over a wireless network such as a cellular provider network (CPN) 14 or a short range wireless access point (WAP) 15, such as Bluetooth, 802.11b, or HomeRF. In either case the bandwidth of the communication channel is typically limited which can degrade the data access performance of the mobile terminal.
During on-line browsing, web pages may be cached in the local memory of the mobile terminal either from having previously visited the web page during an on-line browsing session or from a synchronization session. If the user selects a link wherein the corresponding web page is cached in the local memory, the mobile terminal will retrieve the web page from the local memory rather than download the web page from the Internet. This enhances the performance of the mobile terminal since retrieving web pages from the local memory is typically much faster than downloading web pages from the Internet over a low bandwidth connection. However, conventional browsing programs do not distinguish between links having cached web pages and non-cached web pages. Thus, the user has no indication of how fast information will be displayed on the mobile terminal when clicking through a link.
FIG. 3 shows a newspaper web site comprising a “Top Stories” link 16A, a “Business” link 16B, an “Entertainment” link 16C, and a “Sports” link 16D. In this example, during a synchronization session the web pages 18A linked to the “Top Stories” link 16A and the web page 18B linked to the “Business” link 16B are downloaded to the mobile terminal before the memory allocated to this web site is exhausted. Thus, the web pages 18C linked to the “Entertainment” link 16C and the web pages 18D linked to the “Sports” link 16D are not downloaded to the mobile terminal. FIG. 4 shows that a prior art mobile terminal will display all of the links for the newspaper site, including the “Entertainment” link 16C and “Sports” link 16D, even though these are “dead” links since the linked web pages are not cached in the mobile terminal's memory. If the user clicks on either of these links during an off-line browsing session, an error message is displayed indicating that the selected web page is not available. A similar drawback manifests when browsing the Internet on-line. Referring again to FIG. 3, the web pages 18A and 18B may be cached in the mobile terminal due to a prior synchronization session or having previously browsed these web pages, whereas web pages 18C and 18D may not be cached in the mobile terminal. As illustrated in FIG. 4, the prior art mobile terminal will indiscriminately display the “Top Stories” link 16A, “Business” link 16B, “Entertainment” link 16C, and “Sports” link 16D without indicating whether the corresponding linked web pages are cached by the mobile terminal. Thus, the user cannot determine how fast web pages will be displayed, that is, whether a web page will be displayed quickly due to being cached or whether it will need to be downloaded from the Internet. The user must select each link to discover whether the corresponded linked web page has been cached. This is undesirable since a user may prefer to view only cached web pages in order to conserve battery power and increase browsing performance.
There is, therefore, a need to enhance the performance of a mobile terminal when performing on-line or off-line browsing of Internet web pages.